Activity detection, both friendly and malicious, has long been a priority for computer network administrators. In known public and private computer networks, users employ devices such as desktop computers, laptop computers, tablets, smartphones, browsers, etc. to interact with others through computers and servers that are coupled to the network. Digital data, typically in the form of data packets, are passed along the network by interconnected network devices.
Unfortunately, however, malicious activities can cause harm to the network's software or hardware, or its users. Malicious activities may include unauthorized access or subsequent unpermitted use of network resources and data. Network administrators seek to detect such activities, for example, by searching for patterns of behavior that are abnormal or otherwise vary from the expected use pattern of a particular entity, such as an organization or subset thereof, individual user, IP address, node or group of nodes in the network, etc.
Security appliances are used in known systems to provide network security. The appliance approach involves installing security appliances (which are typically servers or computers configured for providing security) at one or more locations in the network. Once installed, the appliance monitors traffic that traverses the network. Functions provided by the appliance may include malware detection, intrusion detection, unauthorized access or unauthorized use of data, among others. Unfortunately, security appliances cannot easily be scaled to handle temporary or permanent increases in network traffic. Increased network traffic often requires a security vendor to perform an appliance swap or an equally time-consuming appliance upgrade. Appliances also tend to have only limited network visibility because they are typically configured to monitor data traversing the link on which a respective appliance is installed only. Such an appliance will be unaware of activities occurring on other network segments monitored by other appliances and thus cannot use the additional context information pertaining to activities occurring on other network segments to detect a cleverly-designed piece of malware that may be difficult to detect from purely localized information.
Installed software products, rather than security hardware appliances, provide another approach to security for data networks. These products, such as anti-virus or anti-malware software, typically are installed on terminal devices (e.g., desktop and laptop computers, tablets, or smart phones). Data traversing the network between the terminal device is monitored by the installed products to detect malware in either inbound or outbound data. Unfortunately, installed software products also do not perform well in terms of scalability or network visibility. Installed products tend to be disposed locally on the terminal devices and thus also tend to have fairly localized views of the data on the network. They also tend to be installed on hardware that cannot be upgraded easily.